Remove diagrams directory

[jeff-matthews]

Per team conversation on 7/9/19:

• The infographics-library repo should only contain shared infographic components/icons
• draw.io source files can be stored in the same format we use for presentation (SVG)
• There's no need to store diagrams in a separate "diagrams" directory
• Keeps these files in the same repo as devdocs or docs
• We should move sketch files to internal storage (e.g., SharePoint)
• The "Icons" directory is an appropriate use of the infographics repo

[bdenham]

Sounds good, but if we create graphics in draw.io, I’m not sure that SVG files can be imported and edited with draw.io as needed for updates. The drawio xml format is the actual source file for those graphics, so they may need to be stored with the exported SVG files.

[jeff-matthews]

Thanks @bdenham. @dshevtsov seemed convinced that we could use SVG for both source and output, but if that's not the case, we need to confirm.

[bdenham]

Got it. I’ll do some tests later today.